kern/152310: Serial I/O hangs in FreeBSD 8.x

[Ben Cadieux]

>Number:         152310
>Category:       kern
>Synopsis:       Serial I/O hangs in FreeBSD 8.x
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Nov 17 00:20:09 UTC 2010
>Closed-Date:
>Last-Modified:
>Originator:     Ben Cadieux
>Release:        8.1-STABLE
>Organization:
>Environment:
FreeBSD underworld.twinmaple.com 8.1-STABLE FreeBSD 8.1-STABLE #0: Wed Oct 13 15:42:29 PDT 2010     sol at underworld.twinmaple.com:/usr/obj/usr/src/sys/UNDERWORLD  amd64
>Description:
I have HylaFax running in a jail, sending faxouts on /dev/cuau0 - after sending several faxes (~20 - 30), modem communication simply hangs.

I can terminate all faxing processes, reset the modem and attempt to re-initialize it without any luck.  It does not respond at all until I reboot the server.

I found pr kern/140947 which is a very similar report and have verified that I am using puc/uart updated beyond this point.

murgo% pstat -t
      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   COL  SESS  PGID STATE
  sysmouse     0    0    0    0     0    0    0     0     0     0 -
     ttyu0     0    0    0    0     0    0    0 99999     0     0 IC
     ttyu1     0    0    0    0     0    0    0    13     0     0 IC
     ttyu2     0    0    0    0     0    0    0    11     0     0 IC
     ttyv0  1920    0    0  192  1984    0  199  1712 49247 49247 Oicl
     ttyv1  1920    0    0  192  1984    0  199    19 49245 49245 Oil
     ttyv2  1920    0    0  192  1984    0  199     7 49244 49244 Oil
     ttyv3  1920    0    0  192  1984    0  199     7  2228  2228 Oil
     ttyv4  1920    0    0  192  1984    0  199     7  2229  2229 Oil
     ttyv5  1920    0    0  192  1984    0  199     7  2230  2230 Oil
     ttyv6  1920    0    0  192  1984    0  199     7  2231  2231 Oil
     ttyv7  1920    0    0  192  1984    0  199     7  2232  2232 Oil
     ttyv8     0    0    0    0     0    0    0     0     0     0 -
     ttyv9     0    0    0    0     0    0    0     0     0     0 -
     ttyva     0    0    0    0     0    0    0     0     0     0 -
     ttyvb     0    0    0    0     0    0    0     0     0     0 -
     ttyvc     0    0    0    0     0    0    0     0     0     0 -
     ttyvd     0    0    0    0     0    0    0     0     0     0 -
     ttyve     0    0    0    0     0    0    0     0     0     0 -
     ttyvf     0    0    0    0     0    0    0     0     0     0 -
     pts/1     0    0    0    0     0    0    0    12 57369     0 G
     pts/0     0    0    0    0     0    0    0     0 78315     0 G
     pts/2  1920    0    0  192  1984    0  199     7 45529 45534 Oi
    
murgo% dmesg | grep uart   
uart0: <16550 or compatible> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
uart0: [FILTER]
uart1: <16550 or compatible> port 0x2f8-0x2ff irq 3 on acpi0
uart1: [FILTER]
uart2: <16550 or compatible> port 0x3e8-0x3ef irq 5 on acpi0
uart2: [FILTER]
>How-To-Repeat:
Using cuau0 for an hour or so seems to repeat the problem for me.
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: